double curly brace {{
In my understanding, these braces are used to pass python variables to the HTML template. I will give you a simple use case here: For example, I want to pass the value of a variable first_name. In the views.py:
def my_html_template(request):
first_name = 'John Doe'
return render(request, 'my_html_template_name.html', {'first_name': first_name})
And then in the 'my_html_template_name.html', use the dictionary key to retrieve the value:
<p> {{ first_name }} </p>
This will evaluate to:
<p> John Doe </p>
The curly braces are part of Django Template Language
The part encapsulated between double curly braces {{
}}
is nothing but a variable.
That's how DTL, Jinja2 and other template languages work. They have their own set of rules which translates the template in to python and later to HTML code.